This invention relates to a disk reproducing apparatus in which a disk is laid on a turntable to be rotated thereon, more specifically to a disk reproducing apparatus with an up-and-down mechanism for setting the disk on the turntable.
Conventionally, in a disk reproducing apparatus (hereinafter referred to simply as a player), a reproducing stylus is put on a recorded disk laid on a turntable so that information recorded on the disk is read out through the reproducing stylus. The information is composed of video and audio signals, and is recorded on the disk at high density on the basis of, for example, the PCM (pulse code modulation) system. If the surface of the disk is soiled by dust or fingerprints, the reproduced information may involve noise; reproduced pictures may sometimes be blurred by noise. It is therefore necessary to insert the disk into the player to put it on the turntable and to take out the disk from the player without directly touching the disk.
To attain this, the disk is housed in a casing with an opening which is openably closed by means of a lid plate, and is inserted into the player while it is kept in the casing. Inside the player, the lid plate is unlocked from the casing by a holding device, and at the same time the disk and the lid plate are held by the holding device. Thus, if the casing is drawn out from the player in this state, the disk and the lid plate will be left in the player. Then, if the empty casing is inserted into the player after reproducing operation is finished, the disk and the lid plate are released from the holding device, and the lid plate is locked to the casing. By drawing out the casing from the player, therefore, the disk may be removed from the player while it is housed together with the lid plate in the casing.
The player is provided with an up-and-down mechanism for setting on the turntable the disk housed in the player. The up-and-down mechanism includes a disk cradle which can move up and down at the rotation center portion of the turntable to support once the unrecorded central portion of the disk. The disk cradle is driven to descend once below a casing insertion plane so as not to interfere with the casing when the casing with the disk therein is inserted into the player; to ascend to receive the disk when the casing is drawn out after the disk and the lid plate are held by the holding device; to descend to set the disk on the turntable for the reproducing operation; and to ascend to raise the disk up to the casing insertion plane after the reproducing operation is completed.
With the prior art player, however, if an operator cuts by mistake the power supply to the player while keeping the disk on the disk cradle on the casing insertion plane, for example, and leaves the player in this state for a long time, then the disk will be warped with its peripheral portion bent by its own weight because only the central portion of the disk is supported on the disk cradle. Having a bad influence on reproducing accuracy, the warp of the disk would have to be prevented.